Changing color of seaborn plot line

I can’t change the color of a 2d line in seaborn. I have 2 lines in my plot and I want to assign different colors for both of them.

sns.set(style="whitegrid")
data = pd.DataFrame(result_prices, columns=['Size percentage increase'])
data2 = pd.DataFrame(result_sizes, columns=['Size percentage increase'])
sns_plot = sns.lineplot(data=data, color='red', linewidth=2.5)
sns_plot = sns.lineplot(data=data2, linewidth=2.5)
sns_plot.figure.savefig("size_percentage_increase.png")

But color='red' does not change the color, why?

Answer

You have a couple of options here. You can tweak your use of the color parameter, or you can use the palette parameter.

---

palette

Using palette would arguably be the cleaner approach. Ideally, you would make only one call to lineplot when using palette–with the use of hue parameter:

np.random.seed(42)
y0 = pd.DataFrame(np.random.random(20), columns=['value'])
y1 = pd.DataFrame(np.random.random(20), columns=['value'])
y = pd.concat([y0, y1], axis=0, keys=['y0', 'y1']).reset_index()
y = y.rename(columns={'level_0': 'group', 'level_1': 'x'})

sns.lineplot(data=y, x='x', y='value', hue='group', palette=['r', 'g'], linewidth=2.5)

But you could call lineplot for each line similar to how you did in your post:

sns.set(style="whitegrid")
data = pd.DataFrame(result_prices, columns=['Size percentage increase'])
data2 = pd.DataFrame(result_sizes, columns=['Size percentage increase'])
sns_plot = sns.lineplot(data=data, palette=['red'], linewidth=2.5)
sns_plot = sns.lineplot(data=data2, linewidth=2.5)
sns_plot.figure.savefig("size_percentage_increase.png")

---

color

Using the color parameter only appears to work with Series objects. This would be most useful when plotting a single line, rather than when coloring multiple lines in a plot.

Since your dataframes seem to only be one column, you could (A) convert them to Series objects or (B) define x and y parameters when calling lineplot.

Documentation has an example toward the end.

A) Convert to Series

Using your code, it would look something like:

sns.set(style="whitegrid")
data = pd.Series(result_prices)
data2 = pd.Series(result_sizes)
sns_plot = sns.lineplot(data=data, color='red', linewidth=2.5)
sns_plot = sns.lineplot(data=data2, linewidth=2.5)
sns_plot.figure.savefig("size_percentage_increase.png")

As a minimal example:

np.random.seed(42)
y0 = pd.DataFrame(np.random.random(20), columns=['value'])
y1 = pd.DataFrame(np.random.random(20), columns=['value'])
sns.lineplot(data=y0['value'], color='r')
sns.lineplot(data=y1['value'])

B) Define x and y parameters

sns.lineplot(data=y0, x=y0.index, y='value', color='r')
sns.lineplot(data=y1, x=y0.index, y='value')